sig
val step :
Ketrew.Engine.t ->
(bool,
[> `Database of Trakeva.Error.t
| `Database_unavailable of Ketrew_pure.Target.id
| `Missing_data of Ketrew_pure.Target.id
| `Target of [> `Deserilization of string ] ])
Unix_io.Deferred_result.t
val fix_point :
Ketrew.Engine.t ->
([ `Steps of int ],
[> `Database of Trakeva.Error.t
| `Database_unavailable of Ketrew_pure.Target.id
| `Missing_data of Ketrew_pure.Target.id
| `Target of [> `Deserilization of string ] ])
Unix_io.Deferred_result.t
end